Fusion between an internal combustion engine and electric motor--achieving different functions through different power combinations. Automobile hybrid systems combine two motive power sources, such as an internal combustion engine and an electric motor, to take advantage of the benefits provided by these power sources while compensating for each other's shortcomings, resulting in highly efficient driving performance. Although hybrid systems use an electric motor, they do not require external charging, as do electric vehicles. Hybrid systems possess the following four characteristics: 1) Energy-loss reduction The system automatically stops the idling of the engine (idling stop), thus reducing the energy that would normally be wasted. 2) Energy recovery and reuse The energy that would normally be wasted as heat during deceleration and braking is recovered as electrical energy, which is then used to power the starter and the electric motor. 3) Motor assist The electric motor assists the engine during acceleration.
4) High-efficiency operation control The system maximizes the vehicle's overall efficiency by using the electric motor to run the vehicle under operating conditions in which the engine's efficiency is low and by generating electricity under operating conditions in which the engine's efficiency is high. The series/parallel hybrid system has all of these characteristics and therefore provides both superior fuel efficiency and driving performance. There are three types of Hybrid systems from Toyota. The following three major types of hybrid systems are being used in the hybrid vehicles currently on the market: 1) Series hybrid system The engine drives a generator, and an electric motor uses this generated electricity to drive the wheels.
This is called a series hybrid system because the power flows to the wheels in series, i.e., the engine power and the motor power are in series. A series hybrid system can run a small-output engine in the efficient operating region relatively steadily, generate and supply electricity to the electric motor and efficiently charge the battery. It has two motors, a generator (which has the same structure as an electric motor) and an electric motor.
This system is being used in the Coaster Hybrid. 2) Parallel hybrid system In a parallel hybrid system, both the engine and the electric motor drive the wheels, and the drive power from these two sources can be utilized according to the prevailing conditions. This is called a parallel hybrid system because the power flows to the wheels in parallel. In this system, the battery is charged by switching the electric motor to act as a generator, and the electricity from the battery is used to drive the wheels.
Although it has a simple structure, the parallel hybrid system cannot drive the wheels from the electric motor while simultaneously charging the battery since the system has only one motor. 3) Series/parallel hybrid system This system combines the series hybrid system with the parallel hybrid system in order to maximize the benefits of both systems. It has two motors, and depending on the driving conditions, uses only the electric motor or the driving power from both the electric motor and the engine, in order to achieve the highest efficiency level. Furthermore, when necessary, the system drives the wheels while simultaneously generating electricity using a generator. This is the system used in the Prius and the Estima Hybrid.
Since a series hybrid uses its engine to generate electricity for the motor to drive the wheels, the engine and motor do about the same amount of work. A parallel hybrid uses the engine as the main power source, with the motor used only to provide assistance during acceleration. Therefore, the engine is used much more than the motor. In a series/parallel hybrid (THS in the Prius), a power split device divides the power from the engine, so the ratio of power going directly to the wheels and to the generator is continuously variable. Since the motor can run on this electric power as it is generated, the motor is used more than in a parallel system.
Melih ("may-lee") Oztalay, CEO SmartFinds Internet Marketing Web: www.toyotaofbedford.com EMail: melih@hsfideas.com Toyota Ohio state customers now have an online showroom built with Toyota Cleveland Ohio shoppers in mind.
